This invention relates to a process for the production of mineral wool products comprising admixing the starting materials in finely divided form and a hydraulic binder to form a mouldable mixture, moulding the mixture to form small bodies of a desired size (in the following referred to as briquettes), heating the briquettes to a temperature sufficiently high to form a melt and converting the melt thus formed into a mineral wool product.
The specification of Swedish Pat. No. 205.247 discloses a process of the above mentioned type and comprises the use of Portland cement, clay or water glass as hydraulic binder to form the briquettes. However, it has been found that when using such briquettes, the melting conditions in furnaces which ordinarily are used in the production of mineral wool products are not fully satisfactory. This is due to the fact that the compressive strength of such briquettes decrease significantly when the temperature of such briquettes is raised to above about 500.degree. C. Therefore, the briquettes tend to disintegrate and be converted into powder or dust at high furnace temperatures. The presence of such fine materials in the furnace adversely affects the melting process because it counteracts the desired flow of air and flue gases through the furnace. Thus, the presence of these fine materials results in the formation of a large pool of melt having a high temperature whereas it is desired to effect a gradual melting of the surfaces of the briquettes so as to allow a continuous supply of air and a continuous discharge of flue gases.
The object of the invention is to improve the melting conditions by a process of the type described above.